Alkylated cycle oil and the sulfonate derived therefrom

ABSTRACT

A LIGHT CYCLE OIL HAVING A BOILING RANGE OF ABOUT 400 TO 675* F. IS CONTACTED WITH AN ALKYLATION CATALYST UNDER ALKYLATING CONDITIONS SO AS TO PRODUCE A PRODUCT CONTAINING ALKYLATED AROMATICS PRODUCED BY ALKYLATING THE AROMATICS PRESENT IN THE CYCLE OIL WITH THE OLEFINS ALSO PRESENT IN THE CYCLE OIL. THE ALKYLATE, PARTICULARLY AFTER HYDROGEN TREATING, IS USEFUL AS A MOTOR GRADE LUBRICATING OIL AND AS A GENERAL PURPOSE LUBRICATING OIL OR NON-STAINING RUBBER EXTENDER OIL AND WHEN SULFONATED WITH A SULFONATING AGENT AND NEUTRALIZED WITH A BASIC METAL COMPOUND PROVIDES A SUPERIOR LUBRICATING OIL ADDITIVE.

April 13, 1971 A, N DE vAUL-r 3,574,720

ALKYLATED CYCLE OIL AND THE suLFoNATE DERIVED THEREFROM United States Patent O1 3,574,720 Patented Apr. 13, 1971 ice 3,574,720 ALKYLATED CYCLE OIL AND THE SULFONATE DERIVED THEREFROM Albert N. De Vault, Bartlesville, Okla., assigner to Phillips Petroleum Company Filed July 12, 1965, Ser. No. 471,045 Int. Cl. (107e 143/24; C10m 1/40 U.S. Cl. 260-505 5 Claims ABSTRACT OF THE DISCLOSURE A light cycle oil having a boiling range of about 400 to 675 F. is contacted with an alkylation catalyst under alkylating conditions so as to produce a product containing alkylated aromatics produced by alkylating the aromatics present in the cycle oil with the olens also present in the cycle oil. The alkylate, particularly after hydrogen treating, is useful as a motor grade lubricating oil and as a general purpose lubricating oil or non-staining rubber extender oil and when sulfonated with a sulfonating agent and neutralized with a basic metal cornpound provides a superior lubricating oil additive.

This invention relates to the alkylation of the aromatics with the olefins contained in the light cycle oil derived from the catalytic cracking of petroleum hydrocarbons. In one aspect this invention relates to the alkylate obtained by the alkylation of a light cycle oil. In another aspect the invention relates to a metal sulfonate derived from the alkylated cycle oil. In still another aspect the invention relates to a method for producing an alkylate from light cycle oils. In still another aspect the invention relates to a method for producing a sulfonate from the self-alkylate of a light cycle oil.

I have discovered that the aromatics contained in the light cycle oil of a catalytic cracking operation can be alkylated with the olens present in the light cycle oil to produce an alkylate having desirable properties as a product and also providing a superior feed stock for a sulfonation reaction to produce metal sulfonates which are useful as lube oil additives. The light cycle oil has a boiling range of about 400 to 675 F. and can be obtained in the catalytic cracking of hydrocarbons such as topped crudes and gas oil fractions. The light cycle oil contains olens having l2 to 22 carbon atoms per molecule that are, for the most part, long-chain olefins with internal double bonds and at least one but usually not more than three side-chain methyl groups. The cycle oil also contains aromatics which for the most part have benzene, naphthalene, phenanthrene or anthracene nuclei and either hydrogen (at least one) or methyl groups attached to the nuclei. The light cycle oil contains substantially no naphthenes according to nuclear magnetic resonance analysis.

It is an object of this invention to provide an alkylate produced from the aromatics and olefins contained in a light cycle oil. yIt is also an object of this invention to produce a metal sulfonate from the self-alkylate of a light cycle oil. A further object of this invention is the provision of a lubricating oil comprising the self-alkylate of a cycle oil. Still another object of this invention is the provision of metal sulfonate of a hydrogen treated selfalkylate of a cycle oil. Another object is the provision of a method for making a self-alkylate of a light cycle oil and a sulfonate of such alkylate. Other objects and advantages of the invention will be apparent to one skilled in the art upon studying the disclosure including the detailed description of the invention and the appended drawing wherein:

The sole ligure is a schematic flow diagram of the process for producing the self-alkylate and the sulfonate of the invention.

The following detailed description of a speciic embodiment of the invention will be helpful in attaining an understanding of the invention but should be considered as exemplary and should not be construed as unduly limiting the invention.

A light cycle oil produced in the catalytic cracking of a West Texas crude oil and having a boiling range of about 420 to 620 F. was contacted with hydrofluoric acid in liquid phase at 1:1 volume ratio, a temperature of about F., and a reaction timeof about 15 minutes. The effluent hydrocarbon phase was distilled and the fraction boiling above about 675 F. was recovered. It is considered that materials boiling below about 675 F. are non-reactive and/or non-reacted hydrocarbons and are not properly considered as alkylate. A portion of the recovered alkylate was hydrogenated in the presence of a cobalt molybdate catalyst supported on diatomaceous earth. The conditions of the hydrogen treatment were as follows: a liquid hourly space velocity of l; a temperature of about 550 F.; a pressure of about 500 p.s.i.g.; and a hydrogen/alkylate ratio of about 1000 cubic feet/barrel. Properties of the alkylate and the hydrogen-treated alkylate are shown in the following Table I:

The two materials of Table I and a commercial didodecyl benzene (molecular weight=384) were diluted With about one volume of normal heptane per part by weight of hydrocarbon and sulfonated with a gaseous mixture of nitrogen and sulfur trioxide for about 30 to -60 minutes at a maximum temperature of about 100 to F. About one part by weight of S03 was used per six parts by weight of hydrocarbon. The heptane-sulfonic acid mixture was decanted from the acid sludge and filtered to remove traces of sludge.

The sulfonic acids were neutralized with about 300 parts by weight of calcium hydroxide and 600 parts by weight of water per 1500 parts by weight of sulfonic acid. The heptane was stripped out at about 300 F. and a small amount of Stoddard solvent was added and the distillation continued to remove water and Stoddard solvent as an azeotrope. Final traces of water were removed by heating to 400 F. The calcium sulfonate product was then diluted with about equal quantity of Stoddard solvent and ltered to remove inorganic solids. The Stoddard solvent was then removed by distillation, using nitrogen as stripping gas to recover solvent-free calcium sulfonate.

A portion of the calcium sulfonate was over-based by adding to each 18 parts by weight of sulfonate 6 parts by weight of methyl alcohol, 3 parts by weight of calcium hydroxide and 1 part by weight of benzene. Carbon dioxide was bubbled through the mixture for 40 minutes with stirring. Solvents were removed at 300 F. using nitrogen gas as a stripping agent. The product Was diluted with Stoddard solvent and filtered to remove solids. The Stoddard solvent was then removed by heating to about 400 F. and stripping with nitrogen as stripping gas. The calcium sulfonates and the over-based calcium sulfonates Iwere blended in motor oil compositions and were engine tested by the Caterpillar 1-H and LTD Engine Test de- 3 scribed in military specification MIL-L-2104B and compared with a premium grade SAE 10W-30 motor oil known to contain a metal sulfonate. The results of the tests are shown in the following Table II:

4 catalytic cracking operation but can be diverted to other uses if desired. Light cycle oil is passed via conduit 18 to alkylation zone 19 where the aromatics in the oil are alkylated with the olefns present in the oil in the presence TABLE II.-ENGINE TEST DATA1 Hydrogen-treated Alkylate sulfonate alkylate sulfonate Didodecylbenzene sulfonate 10W-30 Total Base Nc.2 112* 104* 23 59* 8 10 Caterpillar l-H engine tests Property:

Pistonfatings, 120 hours, percent (10W values est Top groove carbon Trace 1 2 0 1 First land 18 Trace Clean- Trace laequer 6 Second groove.- Trace lacquer. d 9 lean Second 1and Do. Third groove Do. Third land Do. Fourth groo Do. Shirt Do.

LTD engine tests Engine ratings 180 hours:

Piston varnish (-10), 10=perfect 6 3.3 7.8.

Oil ring plugging (0-100), O=perfect Over-all sludge (0-50) 50=perfect-- Overall varnish (0-50), 50=perfeet l Sulfonates were compounded ln lube oil compositions so as to have about the same concentration of sulfonates (milliequlvalents per gram of RSOs) as in the W-30 lube oil.

2 This is a measure oi the alkaline reserve, and is the number of milligrams of potassium hydroxide equivalent to the amount of acid required to neutralize the alkaline constituents present in one gram of sample to a final pH of 4. The total base numbers followed by an asterisk were obtained by overbasing with CaCOa.

The sulfonates were also tested for corrosion resistance 3() of an alkylation catalyst such as hydrogen uoride; boron according to a modified version of ASTM D 665-60l Procedure A. In the modied version, referred to as the Sohio Rust Rating Test, milliliters of 1 percent acetic acid is used instead of 30 milliliters of distilled water and stirring of the oil-acid mixture is for 16 hours instead of 24 hours. A rating of l0 is perfect. In these tests, 4 weight percent of the sulfonate is blended with a solvent-refined, light neutral oil having a viscositay of 39.5 SUS at 210 F. The results are shown in the following Table III:

TABLE IIL-CORROSION RESISTANCE TESTS Didodecyl- Hydrogentreated benzene Identification alkylate sulfonate 10W-30 Total Base No.1 104* 20 59* 11 10 Sohio rust rating 9. 9 9. 7 9. 5 5. 5 3. 5-4. 0

'Ihe data in the above speciiic embodiment of the invention show that the sulfonate of the hydrogen-treated alkylate is a superior lube oil additive with respect to detergency and corrosion resistance. The self-alkylates were compared to didodecylbenzene because the molecular weights are about the saine. The sulfonates are not only superior to those prepared from pure compounds in detergency properties, but are less expensive to produce. In the preparation of the self-alkylate the fraction of the alkylation effluent boiling below about 675 F. and representing unreacted hydrocarbons is not a waste material but is useful as a kerosene cut or a jet fuel, or it can be returned to the catalytic cracking operation.

Referring now to the drawing, a petroleum hydrocarbon feed stream, for example, a topped West Texas crude, is passed via conduit 10 to a catalytic cracking reaction indicated at 11. The eluent from the catalytic cracking operation is then passed to fractionation zone 12 which can be one or more distillation columns. From the fractionation zone 12 gasoline is recovered via conduit 13; light hydrocarbons are removed via conduit 14; heavy cycle oil is removed via conduit 15; decant oil is removed via conduit 16 and a slurry of oil and catalyst is returned to the catalytic cracking operation via conduit 17. Heavy cycle oil and decant oil are normally recycled to the trifluoride; mixtures of hydrogen fluoride and boron triflnoride; sulfuric acid, or other alkylation catalysts. The alkylate produced in alkylation zone 19 is passed via conduit 21 to hydrogen treating zone 22 wherein the alkylate is contacted with hydrogen in the presence of a metal oxide catalyst such as cobalt molybdate supported on alumina. Hydrogen is added via conduit 23 and light gases are removed via conduit 24. The hydrogen-treated alkylate is passed via conduit 25 to sulfonation zone 26 wherein the hydrogen-treated alkylate is contacted with a sulfonation agent such as S03 introduced via conduit 27 so as to effect sulfonation of the alkylate. The sulfonic acids are passed via conduit 28 to neutralization zone 29 wherein the sulfonic acids are contacted with a basic compound such as calcium hydroxide introduced via conduit 31. The resulting calcium sulfonate is then passed to sulfonate recovery zone 32 via conduit 33 which can be a lter means or centrifuge means for removing excess neutralizing agent, water and/or other diluents as waste via conduit 34. The sulfonate can be removed as product via conduit 35 or can be passed via conduit 36 to overbasing zone 37 wherein the sulfonate is contacted with calcium hydroxide, CO2 and methanol to produce an overbased sulfonate product rwhich can be removed via conduit 38. Calcium hydroxide is added to overbasing zone 37 via conduit 41; carbon dioxide is introduced via conduit 42; and methanol is introduced via conduit 43.

The self-alkylate, particularly the hydrogen-treated selfalkylate, is useful as a motor grade lube oil and as a general purpose lubricating oil and is also an excellent non-staining rubber extender oil. Tests have shown that the self-alkylate is equivalent to non-staining rubber extender oils available on the market.

The alkylation reaction is conventional and the usual catalysts, such as hydrogen fluoride, boron triiiuoride or sulfuric acid, can be utilized. The temperature will usually be about 70 to 100 F. and the catalyst/oil ratio in the reactor will usually be about 1/ l.

Hydrogen treating is accomplished by contacting the feed with hydrogen in the presence of a regenerable metal oxide catalyst at a temperature in the range of about 550 to 800 F. and pressures between about 50 and 800 p.s.i.g. Hydrogen treating removes sulfur and reduces the carbon residue value of the alkylate. Hydrogen treating is well known and will not be described in detail. Cobalt molybdate is a typical hydrogen treating catalyst and is often utilized on a support such as silica, alumina and the like. Other catalysts include nickel molybdate, nickelcobalt molybdate, and the like.

Conventional sulfonation processes are applicable for sulfonating the self-alkylate utilizing such sulfonating agents as fuming sulfuric acid, gaseous S03, liquid S03 dissolved in a diluent such as liquid SO2, chlorosulfonic acid, and the like. An acid sludge is formed which is removed with the acid by decanting, Residual acid sludge is removed by ltering.

The sulfonic acids are neutralized with a basic metal compound such as the oxide or hydroxide of the metal. Any metal oxide or hydroxide can be used; however, the alkaline earth metals are preferred for preparing metal sulfonates as lube oil additives and calcium is VVparticularly preferred because of its availability, low cost and excellence as a component in a lube oil additive. The metal compound is conveniently added as an aqueous slurry or solution and after neutralization the water is removed by ashing at about 30G-400 F. or distilled off as an azeotrope with a naphtha such as Stoddard solvent. Solids are removed by filtering, decanting or centrifuging.

The metal sulfonate can be overbased with CaCO3 by adding to the sulfonate: lime (Ca(OH)2), methanol and CO2 with agitation. A diluent such as benzene or naphtha is often added to reduce the viscosity ofY the sulfonate. The diluents are removed by ilashing or distillation and the solids are removed by filtering, decanting or centrifuging. Other methods of overbasing are known and can be utilized to increase the alkaline reserve ofthe sulfonate. Any method for incorporating into the sulfonate an excess of basic metal compound over that required for neutralization of the sulfonic acids can be utilized to overbase the sulfonate of the invention.

The metal sulfonate will be added to the lube oil in an amount suicient to achieve the desired result and such amount will usually be in the range of about 0.1 to weight percent of the finished lube oil composition but more or less can be added for special uses. Ordinarily about 1.5 to 10 weight percent will be added.

That which is claimed is:

1. The method of producing a lube oil additive which comprises alkylating, under alkylating conditions including a temperature in the range of 70 to 100 F. and in the presence of an alkylation catalyst, in the absence of added benzene, the aromatics in a light cycle oil boiling in the range of about 400 to 675 F., obtained from the catalytic cracking of a petroleum hydrocarbon with the olens also contained in said light cycle oil; treating the alkylated cycle oil boiling above about 675 F. with hydrogen in the presence of a metal oxide hydrogen treating catalyst selected from the group consisting of cobalt molybdate, nickel molybdate and nickel-cobalt molybdate under conditions suitable to remove sulfur including a temperature in the range of 550 to 800 F.; sulfonating the hydrogen treated alkylate with a sulfonating agent at a temperature up to 100 to 110 F.; neutralizing the resulting sulfonic acids with an oxide or hydroxide of an alkaline earth metal; and recovering the resulting metal sulfonate at sulfonating conditions as the product of the process.

2. The method of claim 1 wherein the metal sulfonate is overbased with calcium carbonate.

3. A lube oil additive consisting essentially of the product obtained by l) contacting with an alkylation catalyst at alkylating conditions including a temperature in the range of to 100 F., in the absence of added benzene a substantially naphthene-free light cycle oil produced in theV catalytic cracking ofV ar'petroleum hydrocarbon and boiling in the range of about 400 to 675 F.; (2) reacting the product boiling above about 675 F. obtained by (1) with a sulfonating agent at sulfonating conditions i11- cluding a temperature of up to to 110 F.; and (3) neutralizing the product obtained by (2) with an Oxide or hydroxide of an alkaline earth metal.

4. A lube oil additive comprising the product obtained by alkylating at a temperature in the range of 70 to 100 F. the aromatics with the oleins contained in a substantially naphthene-free light cycle oil produced in the catalytic cracking of a petroleum hydrocarbon; hydrotreating at a temperature'in the range of 550 to 800 F. the resulting alkylate; sulfonating at a temperature of up to 100 to 110 F. the hydrotreated alkylate; and neutralizing the resulting sulfonic acids with an oxide or hydroxide of an alkaline earth metal.

5. The product produced by overbasing the additive of claim 4 with calcium carbonate.

References Cited UNITED STATES PATENTS 2,817,679 12/1957 Verley 260-504 2,920,115 1/1960 Friedman 208-141X 2,645,672 7/ 1953 Schulze 260-671B 2,879,223 3/1959 Cole' et al 260-671GX 3,023,231 2/1962 Logan 260-505NX 3,173,965 3/1965 Pappas et al. 260-671GX 3,288,716 11/1966 Becraft et al 260--671BX FOREIGN PATENTS 691,393 5/1953 Great Britain 260-671G BERNARD HELFIN, Primary Examiner L. DE CRESCENTE, Assistant Examiner U.S. Cl. X.R. 

